1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device, particularly to a method for improving wettability of an organic resin.
2. Related Art
With densification of integrated circuits such as IC, LSI, and VLSI, a semiconductor device has been miniaturized so far. In addition, proportion of wirings has also been increased, and wirings come to influence integration density. Therefore, a technique for lamination of wirings is under development. Thus, in a laminated semiconductor device, a layer made of an organic resin is used as an insulating layer (interlayer insulating layer) that is used for insulating each layer (Reference 1: Japanese Patent Laid-Open No. 2000-3960).
Meanwhile, steps of manufacturing a semiconductor device include a step of etching any thin film into a desired shape using a resist pattern as a mask. Specifically, a thin film is formed over a silicon wafer or a semiconductor thin film by CVD (Chemical Vapor Deposition) or sputtering. A resist is applied thereover and is exposed to light, an ultraviolet ray, an electron beam, or the like to have a desired pattern. Thereafter, the resist is developed to form a resist pattern, and the thin film is etched using the resist pattern as a mask.
However, when a solution including a resist is applied onto an interlayer insulating layer 702 made of an organic resin, the solution including a resist cannot evenly be applied onto the entire surface of the interlayer insulating layer, as shown in FIG. 7A. Consequently, there is a problem that film thickness of a resist becomes uneven. In FIGS. 7A and 7B, reference numeral 703a denotes a region of a resist having even film thickness, and reference numeral 703b denotes a region of a resist that has uneven film thickness and that has thicker film thickness than the region 703a having even film thickness.
Accordingly, it is difficult to form a resist pattern having a desired shape in a desired region at the time of etching the interlayer insulating layer made of an organic resin into any shape or at the time of forming a hole (contact hole) for connecting to a semiconductor region. As a result, there is a problem that a desired region cannot be etched and a decrease in a yield is caused.
In addition, there is a problem that it is difficult to form a semiconductor device having a laminated structure since an organic resin cannot be applied to the entire surface of a first interlayer insulating layer at the time of forming a semiconductor device having a laminated structure with an organic resin.